Typewriting machine



W A DOBSON TYPEWRITING MACHINE Filed May 26, 1930 April 11, 1933.

Patented Apr. 11, 1933 UNITED STATES PATENTQFFICE f WILLIAM A. DODSON, or BRIDGEPORT, CONNECTICUT, AssIenon 'ro ummawoon 1;

ELLIOTT rrsnnn COMPANY, OFVNEW YORK, N. Y., a CORPORATION or DELAWARE TYPEWRITING MACHINE Application filed May 26,

This invention relates to means for winding and automatically reversing an ink-ribbon in a typewriting machine, especially a machine of the portable class, in which all 5 mechanisms must be light, compact, simple, inexpensive, durable and not liable to get out of order.

One of the main objects of the invention is to secure certainty of ribbon-reversing action by the use of afew strong parts, the problem pertaining to ribbon-spools which are placed at opposite sides of the machine, at the front of the platen, where there is no room for ribbon winding and reversing trains.

According to the present invention, near the ends of the ribbon there are fastened buttons, and the ribbon is threaded through eyes in levers placed near the spools. Ac-

cordingly either lever may be engaged and swung by the ribbon-button, when the adja cent spool is nearly unwound.

The levers form part of a crowding train, which includes a shaft extending across the machine under the key-levers, and also includes toothed wheels on theends of said shaft, and crowding dogs for these wheels. Said shaft is also a member of a spool-winding train, having on its ends gears to mesh with pinions, the latter fastened upon the bottom ends of vertical spool-shafts. The main or cross shaft is rotated by means of a ratchet-wheel, driven by a pawl that is operated at every key-stroke. A ribbon-' winding ratchetwheel is placed at the middle of the shaft, and said shaft is swiveled adjacent said ratchet-wheel,' sothat either end of the shaft may be swung or vibrated forwardly, while the other end swings rearwardly. A crowder operating at either end of the shaft, serves to re-engage the winding gears at that end, and to disengage the winding gears at the other end of the main shaft. M A crowding dog at each side of the machine is normally out of engagement with an associated toothed wheel on the cross-shaft, but

the button on the ribbon causes the lever to vibrate, and the latter, being connected by. a V link to the dog,"swings the dog into mesh with its wheel, The dog being caught in the after appear.

1930. S m n esasso.

teeth of the wheel, the rotation of the latter forces the shaft to swing under the pressure or reaction of the dog thereon, as the dog is. turned by the wheel. l v a The invention can be successfully carried' out by mounting all of the aforesaid ribbon winding andv reversingv mechanisms and spools upon the stationary framework of the typewriter, instead of mounting the spools upon the' carriage-shift frame, as heretofore. i Thus there is only a single connection ex-- tending across the machine, and all the parts are very compact. At each side the dog-setting train includes'only a ribbon-'leverand a link, which are compactly placed just within the side walls of the machine' The. entire ribbon-reversing mechanism includes only seven members, namely, two levers, two links, two dogs, and a shaft, the latter being part of the crowding train and also part of the winding train. The shaft is preferably provided with a worm-gearto mesh with the spool-pinion, but the invention .is not. limited to this particular-type of gearing. The gears and wheels may all be of very small diameter, to meet the requirement of compactness. The liability of faulty action of either the winding or the reversing operation is eliminated. Thereare so .few parts that they can all be made heavy and strong, without unduly'adding to the weight of the portable typewriter. The parts are all cheaply made, and simple to manufacture'andiassemble. 7

Other features and .advanta ges will herein In the accompanying. drawing, f Figure 1 is a-fragmentary cross-sectional view, front to rear, through an Underwood portable typewritingmachine"having my invention applied thereto. v

Figure 2 is a fragmentary top plan view of the structure shown in Figure 1.

Figure 3 is a fragmentary perspective view of the right-hand ribbon spool and thefribbon. feeding and reversing mechanism? associated therewith.

Figure 4 is an operational view illustrating the position of the "crowding dog or pawl 7 an Underwood portable typewriting machine wherein types 10 strike against a platen 11 ona platen-shaft 12 journaled in a platencarriage 13; Each type 10 is mounted on a type-bar 14, which is fulcrumed on a-rod 1 5 and is connected by a link 16' to a bell-crank 17, which is pivoted on a rod 18 in a crossly thereto,

and

a ratchet-wheel =43 on a crosswise 'drivewise bell-crank mounting bar 19. A key 20,

for vswinging each type against the platen,

:is mounted onthe forward end of a key-lever 21;,which is fulcrumed about a rod 22 on a main frame 23. A laterally-extending pin .24on the lever 21 engages in a slot 25 in the bell-crank 17, and depression of the key 20 is thus made effective to'swing the associated type 10 against the platen 11.

? Extending under the levers 21, transverseis a universalbar 26 which has two rearwardly-extending arms 27 fastened on a rock-shaft 2.8, which is mounted on brackets 30 fastened to a crosswise channel-bar 31 on the mainframe 23. A compression return springv 32 for each key-lever 21 rests on the bar 31. A tensile'spring 33 fastened to an arm 27 and to'a member (not shown) of the main frame 23 holds the universal bar 26 in its uppermost normal position, which is de- 35 ftermine'd by the arm 27 abutting against a -pin 34. The parts described'above may be of the same construction as like parts in an "Underwood portabletypewriting machine. 1 An inked ribbon 35 is threaded through the vusual ribbon-vibrator 36, which is vibrated (upwardly by instrumentalities to. dispose the ribbon 35 in front of "the printing point on the platen just before each type'lO strikes against theplaten. The

ribbon 35 is mounted ona pair. of ribbonspools 37 one mounted at the rightside of the machineand' one atthe left in a way to be presently described. 1 For feeding 'the ribbon 35 past the.print ing point as the typing proceeds, the ribbon- -spools 37 .are'rotatively connected to the universal-barrock-shaft 28 by instrumentalities including an'u preaching arm 39 fastened on the rock-shaft 28, adjacent'a journal-member 40 mounted on the bar 31, and a drive-pawl *-member 41 which is. loosely fastened to the upper end of the arm 39 extends forwardly has a tooth 42 for engaging the teeth of shaft 44.

talities including a hub- 45 integral withthe --ratche,t-wheel 43:and fastened on the shaft 5approximately' at the center line of the mfii seated on the shelf. (not shown).

plane through the centers of the spools 37. r

v A detent or dog-pawl is pivoted on a screw 51 threaded in the side of the bracket 47 in front of vthe-ratchet-wheel 43 and extends 1 rearwardly under the same, and a tensile spring 52, having one end fastened to the rear end of thepawl 50 and one end fastened to the, drive-pawl 41, holds the dog-pawl in engagement with the ratchet-wheel'43. It can be readily seen that the drive-shaft 44 is compactly positioned below the other operating mechanism of the typewritin g machine and occup es space that heretofore was not used.

For operatively connecting the twospools 37 to the drive-shaft 44, each spool is seated on a spool-head flange 55 integral with a hub 56 which is fastened by a screw'57 to a vertical shaft 58, having an upper end portion extending upwardly past the flange 55 through the usual axial bore of the spool to receive a T in the associated spool 37, and the latter rotates with the flange. For supporting each spool, .a bracket 62'- 'is fastened by a screw 63' to a side member 64 of the main frameand has an inreaching shelf 65 apertured for receiving with arunfit the hub -56,.so that the flange 55 is Each shaft 58 extends downwardly point slightly below theaxis of the driveshaft 44. An inreachin g integral bracket-hi g 66 of the main frame 23 is' positioneda short distance above-the end'of the shaft 58 and is apertured for receiving the same; with a run-v ning fit, the lug 66 and theshelf-65 thereby serving to hold the shaft in vertical'operative position.

LiThe operative conn ection of-the right-hand 7 shaft 58 to thedrive-shaft 44 (see Figure 3) is described below, and it will beunderstood that the same description applies to the connection between the left-hand shaft 58 and the drive-shaft44, except that the direction of the' drive is opposite from the first-named connection. ;A- gear-wheel67 isfastened on the lower end of the shaft 58 by screws 68 threaded :in a hub 69 of the gear on the shaft. A worm 71 is mounted on the shaft 44 near each end for engaging the adjacent gear 67. The worms 71 may be fastened on the shaft 1 by screws 2 threaded in integral hub-elements 73jof the worms. i

. Upon disposal of the shaft the Figure '2 position, it can be seen that by means of the above-described mechanism, depression of the keys 20 will oscillate the universal bar 26, and rotate the shaft 44 step by step, and gradually wind up the ribbon 35 on the left-hand spool 37.

' It is a feature of the present invention to provide compact, inexpensive, positively operating mechanismfor automatically reversing the feed of the ribbon 35 when it is substantially unwound from the paying-off ribbon-spool which, in this description, it will be assumed is the right-hand spool 37. The parts of the ribbon-reversing mechanism described below, except as otherwise noted, are those associated with the righthand ribbon-spool 37. Similar parts are associated with the left-hand spool 37, some of the last-named parts being reversely made as regards corresponding parts associated with the right-hand spool 37. The reversing mechanism includes two usual buttons 74 fastened on the ribbon 35, one button adjacent each end of the ribbon and a. lever 75 having a narrow open slot -7 6 in an upreaching end portion 7 6 through which slot the ribbon 35 is drawn as it is fed past the printing point. The slot 76 is not wide enough to pass the button 74. To mount the lever 75 for having its end portion 7 6* swing away from the right-hand ribbon-spool towards the printing point by the button when it comes against the lever, two integral arms 77 at the side of a body-portion 78 of the lever are bent toward the right-hand spool 37, and are pivotally fastened between two downreaching arms 79 of a U-shaped hanger-member 80, which may befastened to the under side of an inturned annular flange 81 of a ribbon-spool cup 82 seated on the shelf 65 and fastened thereto by screws 83. j

An arm 84 is integrally joined to the lower end of the body-portion 78 and extends downwardly and sidewardly, as illustrated in Figures 2 and 3. The lower end of the arm 84 is connected by a wire link 85 to an upwardly-bent ear 86 of an in reaching lug 87 integrally joined to a crowding pawl 88, which. is pivoted about a shoulder-screw 90 threaded in the adjacent side wall 64 of the main frame 23. The screw 90 is positioned a short distance in the rear of the shaft 44 and the pawl 88 extends forwardly and slightly downwardly, its forward end portion terminating in a tooth 91, as illustrated in Figure 4.

For co-operating with the crowding pawl 88, a ratchet-wheel 92 is fastened on the shaft 44 in front of the tooth 91. It will be noted that the right end of the shaft 44 is disposed in the Figure 2 position away from the gear-wheel 67 when the ribbon is being unwound from the right-hand spool 37, and also the shaft 44 and the ratchetwheel 92 are being rotated clockwise.

tooth 93 of the ratchet-wheel and begins to crowd by a toggle-like action the ratchetwheel and the righthand end of the shaft 44 forward toward the adjacent shafts 58.

The teeth 93 of the ratchet-wheel are pointed or sloped in the opposite direction to the rotation of the ratchet-wheel 92 which insures positive engagement of "the tooth 91 by one of the teeth 93 after the pawl 88 is swung up against the ratchet-wheel 92 and the latter is subsequently rotated by depression of the key-levers 2 The crowding of the shaft 44 moves #0 the right-hand worm 71 toward its associated gear-wheel 67, and at the same time the left-hand worm 71 is gradually moved O lrlt of engagement with the associated gear 6 After a small angular movement of the swiveled shaft 44, caused by action of the pawl 88, the left-hand worm 71 is disengaged, by a minute amount, from its gear 67, and the right-hand worm 71 is brought to a point wherein it is just out of engagement with its associated gear 67.

It is a feature of the present invention to provide light, simple, positive means for quickly moving the worm associated with the paying-out ribbon-spool past the above-noted just-out-of-engagement point into full engagement with its associated gear. In carrying out this feature, a thin plate-member 95 is pivotally mounted on the screw 90 and extends forwardly alongthe side wall 64.

Two substantially semicircular notches or valleys 96 are cut in the member 95 adjacent the shaft 44. The rearmost'notch 96 is positioned whereby the right-hand end portion of the shaft 44 is seated in it: when the ribbon 35 is being paid off the right-hand spool37 prior to the beginning of the above-described crowding action of the pawl 88. The other notch 96 is positioned just forward from the above-described rearmost notch, so that a pointed hill-likeelement 97 left between the notches. As the crowding pawl 88 begins to move the shaft 44' angularly, the latter rides up on the hill-element 97 and'is shortly disposed in the Figure4 position, the notched plateanember 95 being cammed down against the tension of a return spring 98, since the shaft 44 is held against upward I movement by having its end portion extend edge of the foremost notch 96, and the latter then becomes effective through the pow er of the spring 98 to cam the right-hand end of the shaft 44 forward to be seated in the foremost notch and the right-hand worm 71 fully engages the associated gear 67 At the same time the left-hand end of the shaft 44 is swung rearwardly to be seated in its associated rearmost notch 96. It can be seen that other devices, such as miter gears, can be substituted for the worm-and-gear elements of my ribbon-feed-reversing mechanism without departing from the scope of my invention.

Provision of the two notches 96 not only eXpedites the final action of the ribbon-reversing mechanism and effects a quick reversal of the ribbon-feed, but the notches also serve as detents to hold one worm 71 positively in engagement with its associated gear while the other worm is held positively out of engagement with its associated gear. Furthermore the action of the foremost'notch 96, which cams the shaft 44 angularly a considerable amount, moves the ratchet-wheel 92 entirely clear of the pawl 88, whereby the latter is free to be returned to normal position by a spring 100, which has one end fastened to the pawl 88 and the other end to the forward extremity of an inreaching integral shelf 101 of the side wall 64 which supports one end of the channel-bar member 31. The

- downward movement of the notched member 95 is limited by a rearwardly-extending stopfinger 103 engaging a pin 104 fastened in the sidewall 64.

It is another feature of the present invention to provide means which are effective for conveniently reversing, at will, the feed of the ribbon and also for manually winding up the ribbon on either spool. To this end, the right-hand end portion of the shaft 44 extends past the adjacent side wall 64 and through a cut-out section 105 of a usual outer decorative frame 106, and has a knurled thumb-piece 107 fastened on its outer end by a screw 108. .To manuallyreverse the feed of the ribbon 35, it is only necessary to move the thumb-piece 107 forward or rearward. To manually feed the ribbon 35, it is only necessary to rotate the thumb-piece 107. It will be noted that a thumb-piece is not provided on the left-hand end of the shaft 44, since such a thumb-piece is not needed except on one end. With the exception of the thumb-piece, the parts of the ribbon-reversing mechanism associated with the left-hand end of the shaft'44 willbe the equivalent of the partsdescribed above for the right hand end, and will operate in a'similar man ner. It'will be understood, of course, that some of the parts associated with the lefthand end of the shaft 44 are reversely made relative to the parts of the right-hand end,

and will move accordingly in performing I gear-wheel connected to each spool, a worm connectible to: each'of sa1dfigear-wheels, a

single drive shaft carrying one of said worms on each end, a swlve'led mounting for said drive shaft, whereby, uponengagement of one of said worms with its associated gearwheel, the other worm 1s swung out of engagement with its associated gear-wheel, crowding mstrumentalities dependent upon the rotation of the drive shaft for engaging either worm with its associated gear-wheel,.

said instrumentalities including a ratchetwheel on each end of said shaft and a normally idle crowding pawl for each ratchetwheel, and means operable by unwinding movement of said ribbon for moving either of said pawls into engagement with its associated ratchet-wheel, to co-operate therewith to enablethe shaft by its rotation to crowd itself to make a swinging movement upon its swiveled mounting, to cause the ribbon to become rewound upon the empty spool.

2. In a ribbon-spool reversing mechanism for a typewriting machine, the combination with a pair of ribbon-spool-shafts, of a swiveled driving shaft extending between said spool-shafts and movableto be'connected with either of them, a pair, of normally idle crowding devices formoving said shaft about its swiveled mounting alternately in opposite directions, each device including a;

toothed wheel on an end of said swiveled shaft, a pawl having a fixed pivot and a leversystemactuated by the ribbon of said mechanism for moving said pawl to engage said wheel, whereby said crowding devices be-' come alternately effective, and instrumentalities for disabling the crowding device then moving said drive-shaft, said instrumental- 'ltles returning said device to normal position,

and thereafter effective to move said driveshaft an additional amount for connecting it with the paying-01f spool-shaft, whereupon it becomes the winding-up spool-shaft. V

3. In a ribbon-spool reversing mechanism I for a typewriting machlne, the. combination with a pair of ribbon-spool shafts, of a swiveled driving shaft extending between. said spool-shafts and movable to be connected with either offthem, ,a pair of normally idle crowding devices for moving said shaft about its swiveled mounting alternately in opposite directions, each device including a toothed wheel on an end of said shaft, a

pawl having a fixed pivot and a lever-system tive for expediting the last part of the movement of said drive-shaft in either direction and connecting it with one of saidribbonspool-shafts, whereby quick reversal of the feed of said ribbon is secured.

4. In a typewriting machine, the combination with a pair of ribbon-spool shafts, of a driving cross-shaft having means at its ends to gear to the ribbon-spool shafts, said cross-shaft swiveled at its middle to swing either end into working position, toothed members upon the ends of said drive shaft, and ribbon-operated pawls, either of which may be moved by the unwinding movement of the ribbon into engagement with its associated toothed member, to enable the rotation of said shaft to crowd it into a swinging action about its swivel mounting, to throw one end out of engagement with the shaft of the full spool and the other end into engagement with the shaft of the empty spool.

5. In a typewriting machine, the combination with a pair of ribbon-spool shafts, of a driving cross-shaft having means at its ends to gear to the ribbon-spool shafts, said cross-shaft swiveled at its middle to swing either end into working position, toothed members upon the ends of said drive shaft, a ribbon-operable lever adjacent to each spool, a link extending from said lever, a pawl swung by said link into mesh with the adjacent toothed member on said drive shaft, to enable the rotation of said shaft to crowd it into a swinging action about its swivel mounting, to throw one end out of engagement with the shaft of the full spool and the other end into engagement with the shaft of the empty spool, and a spring to return to normal position said pawl, link and lever.

6. In a typewriting machine, the combination with a pair of ribbon-spool shafts, of a driving cross-shaft having means at its ends to gear to the ribbon-spool shafts, sald crossshaft swiveled at its middle to swing either end into working position, toothed members upon the ends of said drive shaft, and ribbonoperated pawls, either of which may be moved by the unwinding movement of the ribbon into engagement with its associated toothed member, to enable the rotation of said shaft to crowd it into a swinging action about its swivel mounting, to throw one end out of engagement with the shaft of the full spool and the other end into engagement with the shaft of the empty spool, yielding means being co-operative with said swiveled drive shaft to complete its swinging motioninto engagement with the emptyrspoolshaft and awayfromthe pawL, j i "Z, In a typewriting machine, the combina: tion with a pair of ribbon-spool shafts of a driving cross-shaft having-means atits' ends to gear to the ribbon-spool shafts, said crossshaft swiveled at itsflmiddleto swing either end into working position, toothed members upon the ends of said drive shaft, and ribbonoperated pawls, either of which may be moved by the unwinding movement of the ribbon into engagement with its associated toothed member, to enable the rotation of said shaft to. crowd it into a swinging action about its swivel mounting, to throw, one end out of engagement with the shaft of the full spool and the other end into engagement with the shaft of the empty spool, the teeth of said toothed member pointing oppositely from the direc-- tion of its rotation, for engaging and lifting the free end of the pawl while the rotation of theshaft crowds the toothed member to swing it away from the pawl.

8. In a typewriting machine, the combination with a pair of ribbon-spool shafts, of a driving cross-shaft having means at its ends to gear to the ribbon-spool shafts, said crossshaft swiveled at its middle to swing either end into working position, toothed members upon the ends of said drive shaft, ribbon-operated pawls, either of which may be moved by the unwinding movement of the ribbon into engagement with its associated toothed member, to enable the rotation of said shaft to crowd it into a swinging action about its swivel mounting, to throw one end out of engagement with the shaft of the full spool and the other end into engagement with the shaft of the 7 empty spool, the teeth of said toothed member pointing oppositely from the direction of its rotation, for engagmg and lifting the free end of the pawl while the rotation of the shaft crowds the toothed member to swing it away from the pawl, and yielding means for moving said toothed member and shaft away from the pawl an additional amount, to free the shaft from the pawl and to swing the shaft into engagement with the empty spool-shaft.

9. In a typewriting machine, the combination with a pair of ribbon-spool shafts, of a driving cross-shaft having means at its ends to gear to the ribbon-spool shafts, said crossshaft swiveled at its middle to swing either end into working position, toothed members upon the ends of said drive shaft, and ribbonoperated pawls, either of which may be moved by the unwinding movement of the ribbon into engagement with its associated toothed member, to enable the rotation of said shaft to crowd it int-o a swinging action about its swivel mounting, to throw one end out of engagement with the shaft of the full sjis lf iidthe aui i; and ihizo ngag ment with the shaft of the empty spool, one end of said shaft beingrextended to projgct beydnd th Ifibhiii-frame, and having a kmifl upon said prbjetibn for windihg the shaft and swing mg it iipon ifs swivel;

VWILLIAM A. DOBSON, 

